Circuit breakers



1958 P. M. CHRISTENSEN 2,824,191

CIRCUIT BREAKERS Filed Feb. 5, 1953 4 Sheets-Sheet l FIE, 3.

IN VEN TOR. F404 A7. (HE/675415531 Feb. 18, 1958 P. M. CHRISTENSEN2,824,191

CIRCUIT BREAKERS Filed Feb. T, 1953 4 Sheets-Sheet 3 1958 P. M.CHRISTENSEN 2,824,191

CIRCUIT BREAKERS Filed Feb. 5, 1953 4 Sheets-Sheet 4 v INVENTOR. P40444. cMe/qra/Ja United States Patent Office 2,824,191 Patented Feb. 18,1958 CIRCUIT BREAKERS Paul M. Christensen, West Orange, N. J., assignorto Federal Electric Products Company, a corporation of DelawareApplication February 5, 1953, Serial No. 335,217

25 Claims. (Cl. 200-116) The present invention relates to multi-polecircuit breakers and to tripping devices and manual operating memberstherefor. More particularly the invention is concerned with a multi-polecircuit breaker which can be. manually opened and closed and which isalso opened automatically at all of the poles thereof upon theoccurrence of an overload in the circuit at any one of the poles.

The primary object of the present invention is the provision of a singlepole circuit breaker unit which is provided with a handle for the manualoperation thereof and which unit has provision for use with one or twoother circuit breaker units which are not provided with handles butwhich are manually operable by said handle whereby said single pole unitmay be used by itself or in conjunction with one or both of the otherunits to form a multipole circuit breaker of the double pole or triplepole type, as the case may be, means being provided to trip all thepoles of the multi-pole circuit breaker upon the occurrence of anoverload or other abnormal condition in the circuit of one of the polesthereof.

Another object is the provision in a circuit breaker of a generallyimproved thermal and magnetic tripping device.

In accordance with the foregoing object, it is a further object toprovide a bi-metallic current-responsive control device which is mountedfor pivotal movement whereby to obviate the necessity for the bending ormechanical flexing thereof upon overload.

Further in accordance with said foregoing object, it is a further objectto provide such a tripping device wherein a spring latch element ismounted separately from the bimetallic control device.

A still further object is the provision of a generally improvedcalibration arrangement for a circuit breaker.

The above and other objects, features and advantages of the presentinvention will be more fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. 1 is a side view of a multi-pole circuit breaker pursuant to thepresent invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a sectional view, on an enlarged scale, taken on the line 33of Fig. 2, the circuit breaker mechanism being illustrated in the closedor circuit making condition thereof;

Fig. 4 is a view similar to Fig. 3, with parts broken away and partssectioned for purposes of illustration, and illustrates the trippedcondition of the circuit breaker mechanism;

Fig. 5 is a fragmentary sectional view taken on the line 5-5 of Fig. 3;

Fig. 6 is a fragmentary sectional view taken on the line 66 of Fig. 3;

Fig. 7 is a fragmentary sectional view taken on the line 77 of Fig. 3; Y4

Fig. 8 is a fragmentary sectional View through a single circuit breakerunit taken on the line 88 of Fig. 3;

Fig. 9 is a fragmentary sectional view taken on the line 99 of Fig. 3;

Fig. 10 is a fragmentary sectional view taken on the line 10-10 of Fig.4;

Fig. ll is a fragmentary end view of a single circuit breaker unit takenin the direction of the arrow 11 in Fig. 3 and illustrates a calibrationopening for the circuit breaker unit;

Fig. 12 is a perspective view of a spring latch member pursuant to thepresent invention;

Fig. 13 is a perspective view of the tripping element in the circuitbreaker unit which is provided with the handle; Fig. 14 is a perspectiveview of the tripping element in one of the other circuit breaker units,

Fig. 15 is a fragmentary view similar to Fig. 3 and illustrates amodification; Fig. 16 is a fragmentary view similar to Fig. 15, with 7parts in section, and illustrates the tripped condition of the circuitbreaker mechanism;

' Fig. 19 is a perspective view of a modified spring latch member; and

Fig. 20 is a perspective view of a modified tripping element in thecircuit breaker unit which is provided with the handle.

The present invention is illustrated as applied to a circuit breaker ofthe type described in application Serial No. 186,013, filed September21, 1950, by Louis W. Cole, now abandoned, and the subject matterthereof being contained in a continuation application Serial Number308,235, filed September 6, 1952, which issued as Patent Number2,692,926, dated October 26, 1954, and assigned to the assignee of thisinvention.

Referring now to the drawings indetail, the multi-pole circuit breaker20 of the present invention is here shown in Fig. 2 as comprising theintermediate single pole circuit breaker unit 22 and the outer singlepole circuit breaker units 24 and 26, said units being disposed inside-by-side relation and interconnected, as hereinafter described indetail, to provide for the concomitant manual operation thereof, as wellas to provide for the automatic tripping of all of said units inresponse to the tripping of one of said units upon occurrence of anoverload. The circuit breaker mechanism for each of said single polecircuit breaker units is generally indicated by the reference numeral 28in Figs. 3 and 4. Said mechanisms are similar and each is enclosedwithin a casing or housing 30 which is formed by a body part 32 and acover or closure part 34 therefor. Each of said parts is formed,preferably by a molding operation, from a suitable insulation materialsuch as, for example, Bakelite and said parts are mutually securedtogether in housing defining relation in a suitable manner, as by meansof the rivets 36. It will be noted that the body part 32 for theintermediate circuit breaker unit 22 differs from the similar body partsof the other circuit breaker units by being provided with an openings 33(Figs. 2, 3 and 4) for the handle 40.

' The circuit breaker mechanism 28 for each unit comprises a stationarycontact 42, a companion movable contact 44, an operating mechanism,generally indi- .cated by the reference numeral 46, and a trip device.50 extends through a slot 56 formed in the housing in- 3 ordertoposition the stationary contact 42 for engagement by .the companionmovable contact. 44. At its outer end, the terminal member 50 isprovided with suitable connecting means 58 for connecting the terminal50 in an electric circuit. At the opposite end of the housing30,provision is made for a prong terminal member .60 which is preferably ofthe. type illustrated and described in the copending application .-ofThomas M. Coleand Paul M. Christensen," Serial No. 127,432, filedNovember 15, 1949, now Patent No. 2,647,225, and'a'ssigned tothe'assignee-hereof. Said prong terminal is adapted to engage 'inasuitable line terminal tocomplete the electric circuitin which thecircuit breaker unit is connected. A flexible conductor- 62 --connectsthe prong terminal 60 to the circuit breaker mechanism, as hereinafterdescribed in detail,"for completing a circuit through the circuitbreaker when the contacts -are=engaged. -In order-to securelyan'd-releasably mount the circuit-breaker unit-on a.panelboard,-a recess64 is defined therein for-engagement bya compa'nion retaining element onthe panelboard,-in the -ma-nner fully illustrated and described in saidlast 'mentio'ned application. Thus the circuit breaker unit isreleasably locked in position at opposite ends thereof by-engagement ofthe prong in 'aeompanion termin'alon the panel-boa'rd and by theengagement 'of'a pan'lboard -securing element in the recess 64.-However, it will he understood-"that the line terminalneed not-be in"the form of a prong but may be of other suitable type.

"Thelrnovable contact 44 is carried on'the free end of a generallyU-shaped switch member 66 (Figs."" 3 5) having-'thespaced legs 68--6Sthereof supported inrecesses' 70- 70, respectively, defined in the legs72-72 of a U-shaped operating member 74. Pursuant to one feature of''the present invention, only the operating member '74 -of theintermediate circuit breaker unit 22 is provided with the aforementionedhandle '40. Referring--to"1igs; Sand 10, the handled-operating memberfor'theintermediate unit 22 is therein designated-by thereferencenumeral 74, and the handleless operating member for the circuitbreakerunit 24, which maybe considered as the left hand unit asviewed-in said figures, is designated by-the reference numeral 74A,, andthe circuit breakerunit 26, which may be' considered as -'the righthandunit, is provided with the handleless operating memberwhich'isdesignated by the reference numeral 74B. The housing for theintermediate'circuit breaker unit 22 is provided with aligned opposinghearing openings 76-76 defined'th'erein for pivotally mounting thelaterally extending pivot portions 78--78 of'the operating'member 74."It will be noted that each of said pivot portions'is provided'with,a'groove '80 defined therein, and further that said pivot portionsterminate inwardly of the outersurfaces -79-79of the companion casing,as" best illustrated 'inFig. 10. The operating member 74A for the "lefthand circuit breaker 24 is provided with a laterally extending pivotportion 82 which -is preferably mounted in a bearing Tecess' 84definedinthe companion coverpart 34 and is 'also' providedwith theopposing pivot portion 86'which is preferably-mounted in a bearingaperture'88- defined'in the companion casing body 32opposite-therecess"82. "fSaid pivot portion 86 is provided with aprojectionor tongue 90 whichextends outwardly ofthe companion. casingfor releasable engagement in the adjacent .groove80'defined in theoperating member'74. "In the. same manner,the operatingmember7'4B"forthe right hand circuit breaker unit 26 is provided with a pivotportionf 92 which is. pivotallymounted infa bearing .recess. 94fde-.finedinjthe companion casing body 32,. and is. also-pro videduwith anopposing pivot portion 96 which :is mounted-in an opposingbearingppening 98.defined,. in thetcompanion casing=coyer 34. 1Aprojection or-itongue 100 provided on the-pivot; portion 96 extendsoutwardly.

of the companion casing for engagement in the adjacent groove -80provided in theoperating member 74. From the foregoing, it will beapparent that when the operating member 74 of the circuit breaker unit24 is interlocked with either or both of the operating members of theleft and right circuit breaker units,- an articulated operating unit isprovided and the handle 40 may be manually operated to concomitantly,operate the various interlocked segments thereof.

. In each circuit breaker. mechanism, ianoperating spring 1021sconnected under tension: between-the s'witcbmember 66 and a releasablecarrier or aCtUat0l': =1041.-WhiCh is pivoted ,on.,a,pivot pin,106supported .in .opposing openings provided "in-the companion housing. Theswitch memberi-fifi-isaconnectedv bynmeans of a flexible conductor 108to the free end of a bi-metallic currentresponsive control element 110which forms a part of the previously mentioned trip device 48, saidcontrol element,'as previously indicated beingconnected by the flexibleconductor .62to the terminal '60.to complete a circuit between the-termin'al""60 and the terminal'SO when the contacts areenga'ged.

The 'switch member 66 'offthe intermediate circuit breakerunit 22 isoperated to manually 'open'and "close the contactsby manipulation "ofthe handle"40. More specifically, movement of the handle in aclockwisedirection "from 'the circluit maldng position thereofillustrated in' Fig. 3, 'carries'the leg's 68-168" of the'switch memberacross tothe left'ofi'theiline of action of the operating springf102which then lbiasesthe switch member'tofthe op'enp'osit-ionithereof,andcauses movement ofthe switch'memberfto 'openj'po'sition with a snapaction. It will'f'be readilyapparentthat whenthe' operating 'm'embers'74A and"7'4B,,'of" the companion circuit breakers, are interlocked withthe operating member 74 "for concomitant movementtherewith;thepreviously described movement'offthefhandlem) will also result in themovement 'of'the'switch meniberstherejof to the open position thereof.

"From said'manual opemposition, eachjof the, interlocked circuit breakerunits are manually closed by reverse operation of the -handle 40.Counter-clockwise movement .of the handle '40ffr0m .the 'open to theclosed positionthereof moyesvthe legs '68-68 of each of'the switchmembers across ,tothe right 'ofrthe line of action of the companionspring 162 which thereupon acts to close the companiomcontacts with .a.snap action.

Each circuiti breaketllnit is. adapted to'be tripped openinstantaneously, to the sposition thereof illustrated in Fig. '4;in'response to overloads above. agpredetermined value, or upon theoccurrence of a short circllit an'd after a'time delay, inthe case,oflesser overloads; .by means of the trip device'48. .Opera'tion ofithetrip device .48, releases the companion actuator 10'4 whereupon theovercenter spring 2102 movesthe .actuatorclockwise, moving the line ofaction of said overcenter spring tothe right of the centerline of thecompanionswitchmember 66. Thereafter thespring .102 acts to movetheswitch member 66 to open position'with a'snap action, said switchmember, actuator 104 andthespring 102 therehetween comprising releasablyrestrainedme'cha'nism released by said; operation of theitripgdevice'lfi. The movement of the actuator I04is limitedbytheengagement of thefree latching end112 there'ofwith the portion 114 of the casing, asillustrated in Fig. 4.

The trip' device'48"comprisesthepreviously mentioned bi-metal element110, :an electromagnet which comprises a movable core element-116-'carried"by a resilient latch member 118, and a companion springbiased armature 120 mounted-for limited'movement. *Pursuantto anotherfeature of the present invention, as will-hereinafter appear indetailjthe-trip deviceaise:includes a 'latch piece for engaging theactuator, which latch piecesi srmounted separately-"from the bimetalelement, being mounted-on said resilient latch member.

Pursuant to a further feature of the present invention, the bi-metalliccontrol element 110 is not fixed but is mounted for pivotal or bodilymovement. Said element is provided adjacent the lower end thereof with apivot pin 122 which is pivotally mounted in opposing bearing portions124 formed in the casing, as best illustrated in Pig. 6. At the lowerend thereof, the unthreaded shank of a screw member 126 extends throughan opening 127 in the bi-metal for threaded engagement in a companionnut 128 which is retained against rotation by suitably formed portions130-130 of the casing. A spring 132 is coiled about the screw 126, beingdisposed between the not 128 and the bi-metal 110, as best illustratedin Fig. 3, for biasing the bi-metal in a counter-clockwise direction. Itwill be noted from Fig. 8 that the core member 116 is a channel orU-shaped yoke and that the bimetal 110 extends between the opposing arms134-134 thereof. Said arms are provided with the inturned flangeportions 136-136, the function of which will presently appear. The coremember 116, as previously indicated, is carried by the latch member 118.More specifically, as best illustrated in Fig. 12, said latch membercomprises the leaf spring 138 which is provided at the lower end thereofwith the angled latch piece 140 secured thereto, as by the rivets 142,and is provided at the upper end thereof with the reversed arcuateportion 144. When said arcuate portion 144 is inserted into a slotdefined by the companion housing portions 146 and 148, said arcuateportion is straightened, the spring is placed under tension and alsobiases the electro-magnetic member 116 to the left, viewing Fig. 3. Thespring 138 is slotted, as at 150, to receive a projection or tongue 152provided on the bight of the electro-magnetic core member 116 formounting the latter upon the latch member 118, as best illustrated inFig. 8. The previously mentioned armature 120 is disposed within arecess 154 defined in the housing and a leaf spring 156 biases saidarmature against the inturned portions 158-158 provided in the housingfor retaining said armature in position, the spring 156 permittinglimited movement of the armature away from said portions 158-158, aswill presently appear.

The latch piece 140 provided on the latch member 118 normally engagesand restrains the actuator in the op erative position thereof, in theclosed condition of the circuit breaker, as illustrated in Fig. 3. Uponthe occurrence of an overload current below a predetermined magnitude orvalue thereof, the bi-metallic control device 110 in the overloadedcircuit is heated and flexes away from the companion actuator 104.During said flexing thereof, the bi-metal will engage the inturnedflange portions 136-136 of the electro-magnetic core 116 and move saidcore in the direction of the arrow 160 in Fig. 3 against the bias ofspring 138 to disengage the latch piece 148 from the end 112 of theactuator 104. The casing parts are recessed at 161-161 to allow for saidmovements of the member 116. If said movement of the core 116 issufficient to cause the latter to engage the armature 120 the latterwill be moved thereby in the same direction against the bias of thespring 156 to prevent damage to the bi-metal. Upon release of theactuator 104 by the latch piece 140, the operating mechanism 46functions in the previously described manner to automatically open thecontacts.

Upon the occurrence of a heavy overload or short circuit above thepreviously mentioned predetermined current magnitude, the currentflowing through the bimetallic element 110 will energize theelectro-magnet core member 116 a suflicient amount to attract thecompanion magnetic armature 120. However, since said armature isretained against movement toward the core member, by the casing portions158-158, the core member 116 will move toward the armature to flex thespring 138 in said direction whereby to release the latch piece 140 fromthe latched engagement with the end 112 of the 6 actuator 104, therebyreleasing the actuator and effecting instantaneous opening of thecontacts.

Pursuant to another feature of the present invention, provision is madefor automatically opening or tripping all of the circuit breaker unitsupon the occurrence of an overload or short circuit in the circuit ofany one of said units. In this connection, the intermediate circuitbreaker unit 22 is provided with a tripping element 162, bestillustrated in Fig. 13. Said element is provided with the laterallyextending pivot portions 164-164 which are pivotally mounted in opposingbearing apertures 166- 166 (Fig. 9) formed in the companion casing. Saidpivot portions are provided with the grooves 168-168 and, as noted fromFig. 9, terminate inwardly of the outer surfaces 169-169 of thecompanion casing. The left hand circuit breaker unit 24 is provided witha tripping element 170, best illustrated in Fig. 14. Said trippingelement is provided with the laterally extending pivot portion 172 whichis pivotally mounted in a bearing recess 174 provided in the companioncasing and with the opposing pivot portion 176 which is pivotallymounted in an opposing bearing aperture 178 provided in said casing.Said latter pivot portion is provided with a projection or tongue 180which engages in the adjacent groove 168 provided in the trippingelement 162. The right hand circuit breaker unit 26 is provided with asimilar tripping element except that the projection is provided on theopposite pivot portion thereof. More specifically, the tripping element182 of said right hand circuit breaker is provided with the pivotportion 184 which is mounted in a bearing recess 186 defined in thecompanion casing and with an opposing pivot portion 188 which ispivotally mounted in an opposing bearing aperture 190 defined in thecasing. Said portion 188 is provided with a projection or tongue 192which extends outwardly from the casing for engagement in the adjacentgroove 168 defined in the tripping element of the intermediate unit.From the foregoing, it will be apparent that the various trippingelements are interlocked for concomitant movement in the same manner asthe previously described operating members, said tripping elementsfroming an articulated trip means or member. Each of the trippingelements is provided with a laterally extending portion 194 having aflat surface 196 and an arcuate surface 198. A spring member 200 (Figs.3 and 4), is secured at one end thereof to the casing, as by thesecuring element 202, and the free end of the spring is disposed in arecess 204 defined in the companion tripping element. It will be notedthat in the closed condition of each circuit breaker unit, the spring200 resiliently disposes the companion tripping element in the positionthereof illustrated in Fig. 3 so that the flat portion 196 thereof isdisposed below the free end 112 of the actuator and in the path ofmovement thereof.

Upon the automatic tripping of any one of the circuit breaker units,each of which has a circuit breaker mechanism independently operableupon overload in the circuit thereof to open said circuit, the actuatorof the tripped unit will be released from the companion latch piece 140and will be moved by the operating spring 102 as previously described,to the position thereof illustrated in Fig. 4 to open the breaker.During such movement, the free end 112 of the actuator strikes the flatsurface 196 of the underlying tripping element, which is one segment ofthe articulated trip member, causing said segment, and therefore, thearticulated trip member to rotate in a counter-clockwise direction, asillustrated in Fig. 4. During said rotation of the articulated tripmeans or member, the depending portions 206-206, of the segments in theother circuit breakers, are rotated into engagement with the companionbi-metallic elements 110, as illustrated in Fig. 4, and will pivot thelatter, as illustrated in said figure, against the bias of springs 132,in a clockwise direction to engage and move the companionelectromagnetic members 116 in the direction of the arrow 160,

whereby;v to: release; the vcompanion actuators. for tripping: It will.be app arent; that and are" operated by the articulated...trip meanstat the:

non-overloaded'poles for gopeningnhecircuitsat the nonoverloadedt poles.,Due to the pivotalmountingof the variousbi-metallic elements toeifect:the bodily move ment thereof the; latter'need not be. bent, or flexedmechanically, when engagediby :the: segments oh the articu latedt tripmember, asheretofore; in order to trip the companion circuit. breakers:Consequently, a smaller amount of; force. is: required. tormoventhe:bi+metal,-.since the;biametal is. pivoted rather; thanzlraving. one endthereof. fixed. as. heretofore;v it' being: alsornotedi that. thebimetalis; engaged: adjacent the; pivot; thereof. to minimizetherequired force. In thiszconnectiomit will be understood that' the.spring: 1 32; iscOmparatiVeIy: weak and will notv interfere: with said;pivotalErnovement. of the companion bimetal; Thisarrangement permits theovercentering springa1t2,-,of the;,circuit breaker which. trips inresponse to the. overload or short'in'the. circuit thereof, totrip; allof thecircuit breaker units-Without requiring the necessity for. a heavyovercentering;spring which, if required, would materially: increase.theisizeof. thespring and. therefore increase the; sizeof each. circuitbreaker.

In addition, aheavy; spring2102' wouldi increase the'pressure. of thelatch-end112of the; actuator 104 against thecompanion. latch pieceitdandthis: is'undesirable due to the fact-that excessive.latch;pressure:tendsto-causeunreliable or non-uniform calibration of thercircuit'breakermechanism. Further, said. increased force: applied at the latchingend-ofthe actuator: would require increased force on the part ofthe bi-metal.to trip the. circuit breaker uponoverload. Theservarious disadvantagesare overcome, through. the use; of; the' pivotally. mounted bodilymovable. bi-metallic element: 110. Further. in this connection, aspreviously indicated,- in order to-decrease the force requiredon'therpart'ofthe bi-xmetal to unlatch the companion. actuatorupon.overload,.the .spring'133 of the latching member is-made in the:form ofa thin leaf spring to provideas. light a spring. action' aspossible when pressing thelatchpieceagainst the. actuator, said springbeing .in :the'form. of. a=straightbar which is maintained under.tension and. which 1 will? not interfere with.

the movement of the bi-metal inthe tripping direction thereof. Furtherin this connection itwill be noted that the latch piece is hardened andpolished to eliminateany burrs which .may be formed'thereon and toprovide. for

good wear, and since the latch apiece forms only a small part of thelatching member'118; most of. which is formed by the comparatively lightspring'mem'ber- 133', the force required on the-rpart of the,binretalto'unlatch the-actuator is kept to a minimum.

Before the contacts can be closed following an auto matic tripping oropening of; the circuit breakers, it is necessary to reset andrelatcheach :circuitrbreaker mechanism. This is accomplished. by movingthe handle 46 clockwise from thetripped position thereof illustrated inFig.- 4. During-said .movementof the handle, each of the interlockedoperating members 74,.74A and74B forming the articulated operating:member,.will rotate in the same direction, aspreviouslydescribed, sothat a leg 72 of each of said operatingimembers,which is in abutmentwith a pin 208-carried by the companion actuator, in the trippedcondition ofrthe'circuit breaker, will move the actuatorzin acounter-clockwise:direction about its pivot ,106. During saidcounter-clockwise movement, the freeend 1120f the-.actuatonwipes pastthe companion tripping element of .the articulatedlrip; member.whereupon the:spr ing .ltlilreturnsthe' tripping elementto the position,thereoflillustrated. in: Fig. 3.. Upon disengage ment ofsaid;elen1e.nts frorrnthecompaniombi-metals, the flexed spring138returns the latch piece .140 and the electromagnetic member 116: to theposition. thereof illustrated in Fig.3. Said, return movement-of: theelectromagnetic member .116 pivots the companion bi-metallic element;in; acounter clockwise: direction; andthe expansion; ofrthez compressed;spring; 132 properlypositions the bi-metal relative toztliememberl-lo,at the'end of said returnzmovement of: the latter illustrated in' Fig.3. The latching pieces1140 are: now in: position to be engaged by thecompanion actuators 104 at theend of: said counter-olock-Wise' movementof said: actuatorsi Thereafter, therhandle 40-is moved in a' counterclockwisedirection to the position thereofillustratedjinFig. 3,. aspreviously described, to closeithe-zcompanion contacts inzeach of thecircuit-breakers.-

Bursuant to another. feature .of' the present invention, each circuitbreaker unit'cani be; calibrated externally. of the casing. In thisconnection; an opening 210' (Figs. 3, 4, 11), is providedin. eachhousing for access to the previouslylmentionedfadjustingzscrew-1-26.Itwill be apparentthat by threading the screw further into the nut 128the bi-metal 11b Will be pivoted in a clockwise directiona-nd thus.move-closer to the flanges ofthe electromagnetic member 116. This willdecrease the amount of flexing of. the bi-metal in: the overloadedcircuit breaker beforeit beginsrto-movec the member 116 in'thedirection-of the arrow lot to disengage latch piece from the actuator104;- Gonversely,- rotation of the screw l-26.-in adirectiorrto withdrawthe same from the nut 128 results in the expansion of the spring 132 topivot the bi-meta-l: 1'10 in a counterrclockwise direction andrequiresagreater amount of fiexing of the bi-metal before-itisefiectivetoca-use'the release of the companion actuator.

From-the foregoing, it will be apparent that the circuitlbreaker unit22is available for use, by itself as a single pole" circuit breaker, onwith either a left ora rightha-nd circuit breakerunit to form a doublepole circuit brea-ke-n-andwithbothta left: and .aright handunit,to forma-t'riplepole 'circuitbreaken Dueto the novel trip device,-.-wliichincludes a pivoted bimetalliccontrol element and a la'tch':piecezmounted separately therefrom, .EIILOVfiICfiIliGI spring whichissufiicient for use. me single :pole circuit breaker" is: also strongenough to trip-a double+poler or a triple-polecircuit-breaker;

ReferringmowrtoFigs. 15"throug-h 20 in'detai-l, there is illustratedamodification of the previously describedconstruction.,.pursuantto'whiohthe force that is necessary'torotatetlie' articulated tripmember for tripping all of the. circuit:breakers is 1 greatly decreased, elements Fig. 20. As thereinlshown,said element is recessed,

as at 2312-, to provide the laterally spaced portions or arms. 214-214,.and is also recessed, as at 216, to provide a seat for the tongue 211.The actuator 104A is similar to theprevicusly described actuator 104,except for the provisionof the transversely extending pin 218 adjacentthe free end .112 thereof. With the circuit breaker mechanism in theclosed condition thereof, as illustrated'in Fig.15, it Will be notedfrom'Fig. 17 that thetonguezllis' disposed in the seat'216 of thetripping element'and that the spring 138 is tensioned and effective tobias' said tripping element to the position thereof illustratedin-said'-figure: In'saidposition, the seati212 underlies the end 112''of' the-actuator 104A, the trip e1ement'162A being disposed in-thepath'ofmovement' thereof. Assumingnow thatthe'circuit breaker trips inresponse to an overload, the bimetal 110 will operate, as previouslydescribed, to move the core member 116 in the direction of the arrow 160in Fig. 16, for efiecting disengagement of the latch piece 140 from theactuating member 104A. Upon said release thereof the actuating member ismoved, as previously described, to the position thereof illustrated inFig. 16 to open the breaker. During said movement, the actuator end 112enters the recess 212, the pin 218 straddling the latter and theopposite ends thereof engaging the spaced arms 214214, as bestillustrated in Fig. 18, to rotate the tripping element to the positionthereof illustrated in Fig. 16.

It willbe understood that in the present modification, the trippingelements in the right and left hand circuit breakers, are substantiallythe same as the tripping element 162A, except for the provision of thegrooved portions 168-468 at each side of the latter. As previouslydescribed in connection with Fig. 9, the right and left hand circuitbreakers have tripping elements which interlock with the intermediatetripping element to form an articulated tripping member. However, it.will be understood that the tripping elements in each of the right andleft hand circuit breaker units are also each provided with a recess 212for engagement by a companion pin 218 carried by the associated actuatorand with a recess 216 for seating a companion tongue 211 carried by theresilient latch member 118A thereof. Therefore, it will be understoodthat upon the occurrence of an overload at any one pole of themulti-pole circuit breaker, the tripping element at said pole will bemoved to the position thereof illustrated in Fig. 16, and the companiontripping elements at other poles, which rotate as a unit therewith, in acounter-clockwise direction viewing Fig. 15, to also move to theposition thereof illustrated in Fig. 16. It will be noted that at eachof the poles which were not overloaded, the effect of said movement ofthe companion tripping element is to carry the companion latch member118A thereof away from the companion actuator 104A to the positionthereof illustrated in Fig. 16, for disengaging the companion latchpiece 140 from the companion actuator 104A to release the latter fortripping the mechanism thereof. Therefore, it will be readily apparentthat, insofar as the circuit breaker mechanisms at the poles which werenot overloaded are concerned, they will trip as a result of the movementof the latch elements 118A thereof by the companion tripping elementsthereof, and'they do not depend on the mechanical flexing of the bimetal110, for said tripping, as in the previously described embodiment.

Upon resetting of the various circuit breaker mechanisms, as previouslydescribed. the resilient latch 118A returns to the position thereofillustrated in Fig. 15 and thereby rotates the companion trippingelement, in a clockwise direction, viewing Fig. 16, from the positionthereof illustrated in Fig. 16, to the position thereof illustrated inFig. 15. In this connection, it will be noted that the tripping elementis automatically repositioned in the operative disposition thereof byits associated resilient latch member whereby to obviate the necessityfor the spring members 200 of the previously described embodiment.

While I have shown and described the preferred embodiments of myinvention, it will be understood that various changes may be made in thepresent invention without departing from the underlying idea orprinciples of the invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent, is:

1. In a circuit breaker having a stationary contact, a movable contactengageable with and disengageable therefrom, releasably restrainedmechanism operable uponrelease thereof to effect disengagement of saidcontacts, and trip means for effecting release of said mechanism uponoverload, said trip means comprising a latch member in latch engagementwith said mechanism, a part carried by said latch member, and a current-responsive control element operable upon said part for disengagingsaid latch member from said mechanism, said part being U-shaped and saidcontrol element being disposed between the arms thereof, said arms beingoppositely flanged for engagement of said element.

2. In a circuit breaker having a stationary contact,

a movable contact engageable with and disengageable therefrom,releasably restrained mechanism operable upon release thereof to effectdisengagement of said contacts, and trip means for effecting release ofsaid mechanism upon overload, said trip means comprising a latch memberin latched engagement with said mecha-- nism, a part carried by saidlatch member, and a cur-- rent-responsive control element operable uponsaid part for disengaging said latch member from said mechanism, saidpart being an electro-magnetic element energized by current flow throughsaid control element, and a companion magnetic member to which said partis attracted upon said energization thereof for disengaging saidlatchmember from said mechanism, said electro-magnetic member beingU-shaped and said control element being disposed between the armsthereof, said arms being oppositely flanged for engagement of saidelement.

3. In a multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof to open said circuit, said circuit breaker mechanism comprisinga movable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mechanism in circuit-closedcondition, said trip device including a current responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open conditionupon said overload, and trip means extending etween said poles andenergized at the overloaded pole for operating the control members atthe other poles to open the circuits thereof, that improvement whichcomprises mounting said control members for bodily movement, whereby toreduce the force required at the overloaded pole to trip all of saidpoles.

4. In a multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof to open said circuit, said circuit breaker mechanism comprisinga movable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mechanism in circuit-closedcondition, said trip device including a current-responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open conditionupon said overload, and trip means extending between said poles andenergized at the overloaded pole for operating the control members atthe other poles to open the circuits thereof, that improvement whichcomprises the pivotal mounting of said control members, whereby toreduce the force required at the overloaded pole to trip all of saidpoles.

5. In a multi-pcle circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof to open said circuit, said circuit breaker mechanism comprisinga movable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mechanism in circuit-closedcondition, said trip device including a current responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open conditionupon said overload, and trip means extending between said poles andenergized at the overloaded pole for operating the control members atthe other poles to open the circuits thereof, that improvement whichcomprises mounting said control members for bodily movement,

'11 whereby to; reduce the force required at the overloaded poleto tripallrof saidpoles, said-control membersiheing thermal-responsivebimetallic strips each mounted for pivotal movement.

6.In a multi-pole circuit. breaker having at each pole thereof a circuitbreaker mechanismindependently operable upon overload in thecircuitthereof toopen said circuit, said circuit breaker mechanismcomprising a movable contact member, an: operating mechanism thereforand atrip device operable to-latchsaid operating mechanism incircuit-closed condition, said trip device including a currentresponsive control member operable to unlatch said trip device from saidoperating mechanism for operating said movable member tocircuit-opencondition upon said overload, and trip means extendingbetween said poles and. energized at the overloaded pole for operatingthe control members at the other poles to open the circuits thereof,that improvement which cornprises mounting said control. members forbodily movement, whereby to reduce the force required at the overloadedpole to trip all. of said poles, said trip device having a part mountedseparately from the control member thereof, saidpartbeing in latchedengagement with thecompanion operating. mechanism.

7. In a mnlti-pole circuit breaker having at each pole thereof acircuit. breaker mechanism independently operable upon overload inthecircuit thereof to open said circuit, said circuit breaker mechanismcomprising a movable contact member; an operating mechanism therefor anda trip device operable to latch said operating mechanism incircuit-closed condition, said trip device includa ing a current.responsive control member operable to unlatch said trip device from saidoperatingmechanism for operating said movable member to circuit-opencondition upon said. overload, and trip means extending be tween saidpoles and energized at the overloaded pole for operating, the controlmembers at the other poles to open the circuits thereof, thatimprovement which comprises mounting said control members for bodilymovement, whereby to-reduce the force required atthe overloaded pole. totrip allof said poles, said trip device having; a partmounted separatelyfrom the control member thereof, said part being in'latched engagementwith the companion operating mechanism, said part being an electro-magnetic. element energized by current flow through the companioncontrol element, and a companion magnetic member to which said part isattracted upon said energization thereof for disengaging said part fromthe companion operating mechanism.

8.- In acircuit breaker having a stationary contact, a movablecontactengageable with and disengageable-therefrom, releasablyrestrained mechanism operable upon release thereofto effectdisengagement ofsaid contacts, and trip. means for effecting release ofsaid mechanism upon overload,-,said.trip means comprisinga latch memberinlatchedengagemenb with said mechanism, apart carried by said'latchmember, and a current-responsive control: element: spaced: from saidpartand operable thereon upon: overload for disengaging said latch memberfrom said mechanism, and means for adjustably varying the, space betweensaid control element and said part fol-calibrating thecircuit breaker.

9. In a circuit breaker having a stationary contact, a movable contactengageable with and disengageable there--. from, releasably restrainedmechanism operable upon release thereof to effect disengagement ofsaidcontacts, and trip means for effecting release of said mechanismupon overload, saidtrip meanscomprising .a latch memberinlatchedengagement with said mechanism, a part carried by said'latchmember, and a current-responsive control element .spacedfrom said partand operable thereonupon overload for disengageing saidlatch member fromsaid mechanism and means. for adjustably varying the space between said.controlelement and said part for calibr t ng the circuit breaker, and ahousing for said latchingengagement with said mechanism, currentresponsive control means spacedfrom said latching means and operablethereon upon overload for efiecting release of said mechanism by saidlatching means, and means for adjustably varying the relativedisposition of said control means and said latching meansfo'rcalibrating'the circuit breaker, said control means being mounted forpivotal movement, and said varying means being operable to adjustablypivot said control means.

1:1.- In a circuit breaker having astationary contact, a

-movable contact engageable with and disengageable therefrom, releasablyrestrained mechanism operable upon release thereof to effectdisengagement of said contacts; and: trip means for effecting release'ofs'aidmechw nism upon over-load, said trip means comprising means in'latching engagement with said mech'anism,- current responsive controlmeans spaced fromsaid latching means and operable thereon upon overloadfor effecting release ofisaid mechanism by said latchingmea'ns,and-meansfor adjustably varying the relative disposition of saidcontrol means' and said latching means for calibrating thecircuitnbreaker, said control means being mounted for pivotalmovement,and-said varying means being operable to iadjustably pivot said-controlmeans, and resilientmeans' biasing saidcontrol means for pivotalmovementin oppo'- sitionito' movement thereof bysaid varying means.

1. 2.111 a-circuit breaker having a'stationary contact, a'=movablecontact engageable with and disengageable tliere" fromandmechanism for effecting automatic disengage ment' thereof uponoverload, atrip mechanism comprising a latch member having uniforminitial latched engage mentwith said first mentioned mechanism and abodily movable pivotally mounted current-responsive control eleme'ntnormally spaced from said latch member andop'erab'le'upon said latchmember for bodily disengagingsaid latch member from said latchedengagement thereof upon overload, apair of magneticmembers supportedseparate'fromand extending'about' said control element, saidmembers-being spacedfr'om each other by a gap and including-onetmembercarried by-said latch memben-an'd means for adjusting said controlelement relative-to saidlatch member without disturbing said initiallatched engag'ernent orsaid'gap for calibrating the circuit-breaker.

13; In a circuit break er having a stationary contact, a-

- movable'contactengageable/with and disengageable there from andmechanismfor eifectingautomatic disengage ment th'ereof upon overload, atrip-mechanism cornpris ing a latch member-having uniform initial'la'tch'ed engagement withsaid first rnentioned m'echanism and a bodilymovablepivotally mounted current-responsive controlele'rnent} normallyspaced-from said latch member and operable-upon said latch member: fer:bodily disengaging said latch member from said latched engagementthereof upon l overload a pair of magnet-ic members supported separatefror'n' and extending about said control element, said membersbei'ngaspaced from" each other by a-gap' and I including ione member' carriedby said latch member, and 1 meansfor adjusting said control elementrelative to said' latclr' member without: disturbing said initiallatched engagement or said gapi for calibrating thecircuit breaker, saidcontrol element being normally: spaced from' said latch memb'er, andsaidcalibration means being operable to vary said spacing.

14.- In a circui-tbreaker having a-stationary contacn amovablecontactengageable with and disengageable there from and mechanismfor effecting automatic disengagement thereof upon overload, a tripmechanism comprising a latch member having uniform initial latchedengagement with said first mentioned mechanism and a bodily movablepivotally mounted current-responsive control element normally spacedfrom said latch memher and operable upon said latch member for bodilydisengaging said latch member from said latched engagement thereof uponoverload, a pair of magnetic members supported separate from andextending about said control element, said members being spaced fromeach other by a gap and including one member carried by said latchmember, and means for adjusting said control element relative to saidlatch member without disturbing said initial latched engagement or saidgap for calibrating the circuit breaker, said control element beingnormally spaced from said latch member, and said calibration means beingoperable to vary said spacing, said circuit breaker having a housing andsaid calibration means being accessible externally thereof.

15. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof to open said circuit, said circuit breaker mechanism comprisinga movable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mech anism in circuit-closedcondition, said trip device including a current responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open conditionupon said overload, and trip means extending between said poles andenergized at the overloaded pole upon operation of the trip devicethereof, and means independent of the control member at each pole andoperable by said trip means at the non-overloaded poles for opening thecircuits of the latter, said tn'p device having a part releasablylatched to said operating mechanism, and said independent means being apart on said trip device positioned for operation by said trip means fordisengaging said latching part from said operating mechanism.

16. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof to open said circuit, said circuit breaker mechanism comprisinga movable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mechanism in circuit-closedcondition, said trip device including a current responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open con ditionupon said overload, and trip means extending between said poles andenergized at the overloaded pole upon operation of the trip devicethereof, and means independent of the control member at each pole andoperable by said trip means at the non-overloaded poles for opening thecircuits of the latter, said trip device having a part releasablylatched to said operating mechanism, and said independent means being apart on said trip device positioned for operation by said trip means fordisengaging said latching part from said operating mechanism, and saidtrip device having a resilient part for biasing said trip means to theoperative disposition thereof.

17. A mult-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof to open said circuit, said circuit breaker mechanism comprisinga movable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mechanism in circuit-closedcondition, said trip device including a current responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open conditionupon said overload, and an articulated trip member 14 extending betweensaid poles and having a segment at each pole energized at the overloadedpole for operating said trip member, and means at each pole operable bythe associated segment for operating the trip device thereofindependently of the control member thereof.

18. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof toopen said circuit, said circuit breaker mechanism comprising amovable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mesh anism in circuit-closedcondition, said trip device including a current responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open conditionupon said overload, and an articulated trip member extending betweensaid poles and having a segment at each pole energized at the overloadedpole for operating said trip member, and means at each pole operable bythe associated segment for operating the trip device thereofindependently of the control member thereof, said trip device having anelement engaged by the associated segment for operating said trip deviceto unlatch its associated operating mechanism.

19. A multi-pole circuit breaker having at each pole thereof a circuitbreaker mechanism independently operable upon overload in the circuitthereof to open said circuit, said circuit breaker mechanism comprisinga movable contact member, an operating mechanism therefor and a tripdevice operable to latch said operating mechanism in circuit-closedcondition, said trip device including a current responsive controlmember operable to unlatch said trip device from said operatingmechanism for operating said movable member to circuit-open conditionupon said overload, and an articulated trip member extending betweensaid poles and having a segment at each pole energized at the overloadedpole for operating said trip member, and means at each pole operable bythe associated segment for operating the trip device thereofindependently of the control member thereof, said trip device having anelement engaged by the associated segment for operating said trip deviceto unlatch its associated operating mechanism, and means biasing saidelement for disposing said associated segment in operative dispositionthereof.

20. A multi-pole circuit breaker including multiple pairs of contactsand corresponding operating mechanisms and overload release means forsaid contacts, each of said operating mechanisms including a rockableoperating element, the operating elements of said mechanisms beingaxially aligned, said circuit breaker comprising an insulating casingcomprising a plurality of stacked casing walls generally disposed inparallel planes transverse to said coaxial operating members, each ofsaid mechanisms being contained in a cavity provided between arespective confronting pair of said walls, each of said operatingelements being supported by bearings formed in the respectiveconfronting walls containing the related contact operating mechanism,said operating elements being keyed together internally of the casingfor conjoint operation, and

only one of said operating elements including an integral handleprojecting externally of the casing through an opening therein.

21. A multi-pole circuit breaker including multiple pairs of contactsand corresponding operating mechanisms and overload release means forsaid contacts, each of said operating mechanisms including a rockableoperating element, the operating elements of said mechanisms beingaxially aligned, said circuit breaker comprising an insulating casingcomprising a plurality of stacked casing walls generally disposed inparallel planes transverse to said coaxial operating members, each ofsaid mechanisms being contained in a cavity provided between arespective confronting pair of said walls, each of said operatingelements being supported by bearings formed in the respec riveconfronting walls'c'ontainirig the related contact operating mechanism,said operating elements having interengaging tongue and groove endportions extending through openings in their bearing walls enforcingconjoint operation, and only one of said operating eleme'nts includingan integral handle projecting externally of the casing through anopening therein.

22. A circuit breaker having a stationary contact, an operating means, amovable contact member pivoted on said operating means to engage and todisengage the stationary contact for closing and opening the circuit,respectively, an actuator member mounted for movement betweencircuit-closed and circuit-open positions, respectively, thereof, and anovercentering springinterconnected between said members for effectingopening and closing movements of said movable contact memberg means forlatching said actuator in the circuit closed condition thereof,electro-magnetic control means for releasing saidactua'tor in responseto predetermined overload conditions comprising a magnetic membercarried by said latching means and a cooperating magnetic member mountedadjacent said first magnetic member, and a current-responsive controlelement spaced from said magnetic member and operable thereon uponoverload for disengaging said latch means from said actuator, and meansfor adjustably varying a space between said control element and saidmagnetic member for calibrating the circuit breaker;

23. In a multi-pole circuit breaker having at'each pole thereofa circuitbreaker mechanism'comprising a movable contact member, an-operatingmechanism therefor and a trip device operable to latch said operatingmechanism in circuit-closed condition, said trip device including facurrent-responsive control member operable to unlatcn said trip devicefrom said operating mechanism for operating said movable member tocircuit-opencondition upon said overload, and trip means extendingbetween "said poles and energized at the overloaded pole foroperatingthe control members at' the other poles to open the circuitsthereof, each of said control members being-mounted on a pivot formovement as anentity whereby to reduce the force required at theoverload pole to trip all of said poles. V

24. A multi-pole circuit breaker havingateach pole thereof a circuitbreaker mechanism operable'npori'thei occurrence of predeterminedcurrent'in the circuit thereof to open said circuit, each of saidmechanisms comprising a movable contact member, an actuator meansoperatively connected to said movable contact member and alatching meansfor latching its associatedactuator means in circuit closed dispositionthereof and for releasing the same for operating said movable member tocircuit-open condition upon said occurrence, and meansoperatively'common to all poles of said circuit breaker and disposed for operationby 2. released actuator means upon said occurrence in the associatedcircuit of said released actuator means for operating thecircuit-breaker mechanismat a com-1 panion pole to the-circui't-opencondition thereof, said mechamsm including a current responsive controlelement operable upon said latching-means in response to predeterminedcurrent to release its associatedactuator;

and said means common to all of said poles being operable upon thecontrol elements at the other poles torelease the actuatorsthereoi v I25. A multi-pole circuit breaker having at eaclrpole thereof a circuitbreaker mechanism operable upon the occurrence of predetermined currentin the circuit thereof to open said circuit, each of said mechanismscomprising a movable contact member, an actuator means operativelyconnected to said movable contact member and a latching means forlatching its associated actuator means in circuitfclosed dispositionthereof and for releasing the saln'e for operating said movable memberto circuit-open conditionupon said'occurrence, and means operativelycommon to all poles of said circuit breaker and disposed for operationby a released actuator means upon said occurrence in the associatedcircuit of said released actuator means for operating thecircuit-breaker mechanism at a coinpanionpole to the circuit-opencondition thereof, said mechanism includinga currentresponsive' controlelement operable upon said latchingpmean slin response'to predeterminedcurrent to release its associated actuator, and said means common to,all of said poles being operable upon the control elements atthe otherpoles to release the actuators thereof; each latching means having anelectro magnetic member'energized by the associated control means and acompanion electro-magnetic member mounted adjacent thereto, and' saidcontrolmeans being operableon the associated first mentionedelectromagnetic member to release'the associated actuator.

nr' iics" Cited" in the file of patent UNIT-ED STATES PATENTS 2035,24etfla1;' Mar. 31, 1,936 2,065,357" Venn-6on1 De 22', 1936 2,070,305;"Jennings" Feb. 9, 1937 2,096,544" ra kson t nnr 0819,1937. 2,099,585Yon 'Hoorn' Nov, 16,1937 2,107,246 166155 11-13;; Feb.1,19'3 8 2,132,629oer; 11; 1938' 2,166,555 g tin 18, 1939, 2184372 Von Hoorn' Dec. 2,6;,939 2,229,412 Jennings Jan; 21, 19.41, 2,284,825 lenilin gs 'et a1.June 2; 1942. 2,532,496 Baxter Qct. 26, 1943 2,416,163 'F b.' 18, 19472,416,170 Feb, 1 1947 2,419,125 A Apr. 115, 1947 2,421,830 0 16 et1:22,; June 10, 1947 2,425,983 Bingenheimer Augl 19, 1947 2,426,880Jackson et a1. Sept. 2, 19,47 2,447,652 Iennings" Aug. 24, 19482,459,588 s nat 5611 Jan. 18; 1949, 2,568,423 wa11 fer e't'a'l. Sept;18, 1951 2,573,30 Casey Oct. 30," 1951 2,601,638 Rypi'nski June 24, 19522,618,716 Boller'et'al.' Nov. 18, 1952 2,659,2 0; career 61, Aug. 25,1953 2,654,008 our etal Sept. 29; 1953, 2658973 oaSey- N61 10, 19532,662,949: Christensen'etal; Dec. 15, 1953 2,663,773; Drobneyet al. Dec.22, 1953 2,6 8,20 Edrn'dnds Feb. 2, 1954 2,673,264 c616 Ma 23, 1954 2572025 D ye' r Apr. 27, 1954 2,677,026] Bingehein e'r Apr. 27, 19542,678,359 Bril'rr'lfield May 11, 1954 2,689,285 Drobney et al Sept. 14,1954

